Such an elegant method of seed dispersal. Dipterocarpus alatus seed ยางนา. Plentiful where I go with my dogs. Drift downwards like miniature helicopters and can fall over 60m. from the tree. Numerous scientists have studied their motion and and terminal velocity. Resin is collected for eg draught-proofing of boats. Bark used in traditional medicine, for rheumatism and diseases of the liver. I say good luck to those seeds. #nature